PROBLEM
However, if User 1 adds a new event, that new event never shows up in User 2's calendar. Same goes if User 1 deletes an event, it never refreshes in User 2's calendar. The only way we've been able to force the calendar to refresh is to (1) reboot the phone or (2) disable/re-enable the calendar in the Mail, Contacts, and Calendars settings.

Has anyone experienced this issue and/or have a solution/workaround? We are running Zimbra 8.0.6_GA.5922.NETWORK and iOS 7.04.

My experience with a single shared calendar is that sometimes the events show up, but sometimes they do not. If they do not, the only fix is to disable/re-enable the calendar in the Mail, Contacts, and Calendars settings on each iPhone.

There doesn't seem to be a repeatable set of steps that gets the calendars on the phones into this state. I've tried:
- Creating calendar events on the iPhones, after a calendar refresh the events typically show up on both phones.
- Creating calendar events on Webmail, after a calendar refresh the events typically show up on both phones.
- Modifying calendar events on the iPhones and Webmail.

Within the Webmail calendar account settings, I have the following setting enabled: "Enable delegation for Apple iCal CalDAV client"